Physical and electrochemical characteristics of supercapacitors based on carbide derived carbon electrodes in aqueous electrolytes

FIB-SEM, XPS and gas adsorption methods have been used for the characterisation of physical properties of microporous carbide derived carbon electrodes prepared from Mo2C at 600 °C (noted as CDC-Mo2C). Cyclic voltammetry, constant current charge/discharge, and electrochemical impedance spectroscopy have been applied to establish the electrochemical characteristics for supercapacitors consisting of the 1 M Na2SO4, KOH, tetraethyl ammonium iodide or 6 M KOH aqueous electrolyte and CDC-Mo2C electrodes. The N2 sorption values obtained have been correlated with electrochemical characteristics for supercapacitors in various aqueous electrolytes. The maximum gravimetric energy, Emax, and gravimetric power, Pmax, for supercapacitors (taking into consideration the active material weight) have been obtained at cell voltage 0.9 V for 6 M KOH aqueous supercapacitor (Emax = 5.7 Wh kg−1 and Pmax = 43 kW kg−1). For 1 M TEAI based SC somewhat higher Emax (6.2 Wh kg−1) and comparatively low Pmax (7.0 kW kg−1) have been calculated.